#define  _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
#include<stdlib.h>
typedef struct ListNode ListNode;
struct ListNode* reverseList(struct ListNode* head) {
	if (head == NULL)
		return head;
	ListNode* n1;
	ListNode* n2;
	ListNode* n3;

	n1 = NULL; n2 = head; n3 = n2->next;
	while (n2)
	{
		n2->next = n1;
		n1 = n2;
		n2 = n3;

	}
	return n1;
}
int main()
{

}